This invention relates to metal roof construction.
Curbs are constructed on metal roofs around skylights and mechanical equipment such as heating or air condition units, to divert rain precipitation around the unit. The curbs are usually constructed as a rectangle whose side walls are parallel to corresponding sides of the roof. Where the roof has a slope, normally the upslope and downslope curbs are perpendicular to the dip of the roof. As a result, water tends to collect along the upslope curb, and may leak past the curb or cause premature corrosion. U.S. Pat. No. 4,413,450, Pat. No. 5,522,189 and Pat. No. 5,027,576 are representative of prior curbs, installed orthogonally on a roof so that the upslope curb is perpendicular to the dip of the roof.